Subaru 2009 IMPREZA Service Manual page 1451

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
1 CHECK CURRENT DATA.
1) Turn the ignition switch to ON.
2) Read the data of fuel tank pressure sensor
signal using the Subaru Select Monitor or gen-
eral scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
2 CHECK HARNESS BETWEEN ECM AND
FUEL TANK PRESSURE SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from the fuel tank
pressure sensor.
3) Turn the ignition switch to ON.
4) Read the data of fuel tank pressure sensor
signal using the Subaru Select Monitor or gen-
eral scan tool.
NOTE:
• Subaru Select Monitor
For detailed operation procedures, refer to
"READ CURRENT DATA FOR ENGINE". <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>
• General scan tool
For detailed operation procedures, refer to the
general scan tool operation manual.
3 CHECK HARNESS BETWEEN ECM AND
FUEL TANK PRESSURE SENSOR CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness between
fuel tank pressure sensor connector and engine
ground.
Connector & terminal
(R47) No. 2 — Engine ground:
4 CHECK POOR CONTACT.
Check for poor contact of the fuel tank pressure
sensor connector.
Check
Is the measured value 7.95 kPa
(59.6 mmHg, 2.347 inHg) or
more?
Is the measured value 7.95 kPa
(59.6 mmHg, 2.347 inHg) or
more?
Is the resistance less than 5 ? Go to step 4.
Is there poor contact of fuel
tank pressure sensor connec-
tor?
EN(H4DOTC)(diag)-230
Yes No
Go to step 2. Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.
NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.
Repair the short Go to step 3.
circuit to power in
the harness
between ECM and
fuel tank pressure
sensor connector.
Repair the harness
and connector.
NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
ECM and fuel tank
pressure
connector
• Poor contact of
ECM connector
• Poor contact of
coupling connector
Repair the poor Replace the fuel
contact of fuel tank tank pressure sen-
pressure sensor sor. <Ref. to
connector. EC(H4DOTC)-18,
Fuel Tank Pres-
sure Sensor.>
sensor